contact microphone

With a Sound + Vision exhibition coming up, the folks over at Seaweed Factory decided they needed something big. Somehow they landed on building a giant pinata that responds to being walloped with a stick by playing MIDI notes. The end result is called the Trojan Chorus. Instead of Greek soldiers, though, the pinata is filled with electronics and candy.

The pinata was constructed out of cardboard and more colored tissue paper than we care to imagine. The horse stands seven feet tall and was built with a little more structural integrity than a normal pinata. Check out the ‘making of’ video for the pinata here.

From what we can tell, the electronics are 24 contact microphones implanted all over the inside of the pinata. Impacts on these contact mics are recorded by a small dev board, transcribed to serial data, and sent to a computer. You can check out the electronics in action right here. A horse neighing MIDI notes may sound fairly weird, but similar setup could be added to make the Trojan Chorus cry out in pain.

[Leafcutter] is no stranger to messing around with piezo elements, and after seeing [Collin’s] tutorial on making your own piezo crystals at home, he knew he had to give it a try. He stopped by the grocery store to fetch all of the ingredients, then followed [Collin’s] instructions to the letter…well, almost. It seems that he might have cooled the solution too quickly, so he found himself with a jar full of tiny, barely usable piezo crystals instead of larger ones like [Collin] was able to produce.

Undeterred, he decided to see if the stuff was any good, and rigged up a makeshift contact microphone using some conductive foil and a clamp. He piped the output to his amplifier, and wouldn’t you know it…it worked!

He has a small sound clip of what the mic sounded like on his site, and it worked pretty darn well despite the crystal’s tiny size. He is going to give the whole process another go, so we hope to see more experiments with bigger crystals in the near future.